Welcome to Solid State Guitar Amp Forum | DIY Guitar Amplifiers. Please login or sign up.

March 28, 2024, 09:17:32 AM

Login with username, password and session length

Recent Posts

 

Bass amp behaving strange. Please Help

Started by ozzu2000, April 23, 2013, 06:19:15 PM

Previous topic - Next topic

ozzu2000

I recently bought a second hand bass amp, and today it started to crackle and distort the sound (in a bad way), for some instants it might not give any sound at all. I've tried with another instrument, and different cables, and the plug seems fine. The problem comes and goes.

Do you have any guesses?
Could a fault in the power supply lead to an instability like this one?

Oh, another thing, that I thought was normal (might still be) this amp gives a loud pop everytime I turn it on... is this normal?
Its a 15W Crate bass practice amp.

Thanks in advance! :)

Roly

Have you tried giving it a good whack over the nose with a rolled up newspaper?   ;)


Crate, but the exact model ID will help.

This sort of fault is very frequently dirt where it shouldn't be (or possibly a broken solder joint) rather than an actual electronic problem.

Does the fault react to;

- wiggling the lead in the input socket?

- movement of any of the controls?

- thumping the case?

- does it have Effects Send and Return, or Preamp Out, Main In sockets?  If so try bridging these with a known good lead and see if that makes any difference.

Turn on/off pops are a different problem that we can get around to, but one thing at a time.
If you say theory and practice don't agree you haven't applied enough theory.

Enzo

Please, what MODEL is your 15w Crate?

Ball up your fist and whack the top of the amp.  Does that bring it back, even for a moment?  Or if it is making sound now, will that make it quit?  Whacking exposes loose connections inside.

Good chance you have solder joints needing reflow.

ozzu2000

Its a Crate BT15
http://www.crateamps.com/pdf/manuals/BT15_OM.pdf

It's working fine now, I whacked it, and tried to reproduce the problem but with no result.
I'll try all that next time the problem appears.

Thanks! :)

Roly

Both the external speaker and headphone sockets have switch contacts to disconnect the internal speaker when anything is plugged in to them, and these very frequently get dirty over time and intermittent in just the way you described.  A shot of a commercial contact cleaner such as Deoxit, or metho, followed by working a plug in and out a few times to scrub the contacts generally fixes this.
If you say theory and practice don't agree you haven't applied enough theory.